Effect of nitric oxide and TH1/TH2 cytokine supplementation over ectopic endometrial tissue growth in a murine model of endometriosis.

Using a murine model, we evaluated the growth of ectopic endometrial tissue in the presence of T helper 1 (Th1) or Th2 cytokines or a nitric oxide donor (S-nitroso-N-acetyl-penicillamine [SNAP]). Female mice were autografted with endometrial tissue in the peritoneum. Different combinations and concentrations of cytokines or SNAP were injected intraperitoneally for 8 weeks. Implants were recovered, measured, and weighed. Cytokines were determined in plasma. Implants (weight and area) were smaller in mice that received interferon γ plus interleukin 2 (IFN-γ + IL-2) compared to mice treated with IL-2, IL-4 + IL-10 or saline solution, and saline solution compared to different concentrations of SNAP. The IL-2, IFN-γ, and IL-4 concentrations in plasma decreased in accordance with the increase in SNAP concentrations compared to saline solution. The promotion of a Th1 milieu in the peritoneum reduced the weight and area of the implant. Different concentrations of SNAP suppressed Th1 and Th2 cytokines and enabled the growth of the implant in this murine model.